Water-tight wrist-watch cases



Oct. 13, 1964 TSUNEO OJlMA 3,152,438

WATER-TIGHT WRIST-WATCH CASES Filed Nov. 2, 1962 United States Patent 3,152,438 WATER-TIGHT WRIST-WATCH CASES Tsuneo Ojima, 133 Tokiwadai Itabashi-ku,

Tokyo, Japan Filed Nov. 2, 1962, Ser. No. 235,052 1 Claim. (Cl. 58-90) This invention relates to wrist-watches, and more particularly to water-tight cases of wrist-watches of generally square or rectangular configuration.

A conventional water-tight wrist-watch case comprises one or more packing rings of resilient material for preventing water from entering into the case. The packing ring is held in compression between the body of the case and the removable cover thereof by suitable means. When the watch case is of generally circular shape, cooperating screw threads are provided on the body and the cover, respectively, for closing the case, and the packing ring is subjected to a compressive force when the body and the cover are screwed up together to close the case. In this case, however, the packing ring is subjected to a kind of abrasive effect when the case cover is being screwed up towards the case body in rubbing contact with the packing ring, and consequently is damaged or at least deformed to affect the sealing effect. In addition, the screw-thread engagement between the case body and cover is apt to become loose incidentally, resulting in loss of Water-tightness. In order to avoid such a result, and also when the case is of generally square or rectangular shape, the case body and cover are secured together by means of a plurality of set screws passing through holes in the cover and screwed into tapped holes formed in the case body, with the packing ring held under compression therebetween. In such a case, the set screws employed are naturally so small and short that they cannot provide ample force for holding the packing ring under suflicient compression to assure the requisite water-tightness. In addition, the set screws may be screwed off incidentally.

Accordingly, it is the main object of the present invention to provide positively water-tight wrist-watch cases of generally square or rectangular form, with no fear of damaging the packing rings or of incidental failure in Water-tightness.

Another object of the present invention is to provide water-tight wrist-watch cases simple in construction and economical in manufacture.

Other objects and particularities of the present invention will be made obvious by the following detailed description of a preferred embodiment of the invention with reference to the accompanying drawings, in which:

FIG. 1 is a general plan view of the wrist-watch case;

FIG. 2 is a partial vertical sectional view of the case in a larger scale; and

FIG. 3 is a partial end elevational view of the case.

Referring to the drawings, the watch case shown is of generally rectangular configuration, and comprises a watch holder ring 1 for holding therein a watch casing 3 containing watch-Works, not shown, and provided with a conventional dial plate 4 mounted thereon as usual. The watch holder 1 is a generally rectangular metal ring, around which a metal ring 2 snugly fits. The ring 2 supports the holder ring 1, but is movable up and down rela tive to the latter. The supporter ring 2 is provided with an upper internal flange 2, under which a rectangular glass plate 5 is held at its peripheral portion. A packing ring 6 of generally rectangular configuration is interposed between the peripheral portion of the glass plate 5 and the upper face of the holder ring 1. Alternatively, the packing ring 6 may be interposed between the flange 2 and the glass plate 5.

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The watch case has a back cover 7 provided with an upwardly extending peripheral flange 7 which extends into a groove 8 of the corresponding configuration formed in the lower face of the holder ring 1. In the groove 8, a packing ring 9 of the corresponding configuration is interposed between the groove bottom and the flange 7.

The supporter ring 2 has two pairs of support arms 10 and 10' fixed thereto at its opposite sides, and a bandengaging rod 11 is mounted between the two arms 10 and 10' of each pair for anchoring thereto a conventional watch-band, not shown, as usual. There is mounted an additional rod 12 between the arms 10 and 10' of each pair, adjacent to the support ring 2 proper and in parallel with the band-anchoring rod 11, and a locking plate 13 is pivotally mounted on each rod 12, one side edge of the plate being shaped into a loop and snugly embracing the rod 12. Each locking plate 13 has its free side edge portion 13 bent into a hook shape. The back cover 7 also is provided with two pairs of fixed arms 14 at its opposite sides, and a locking rod 16 is mounted between the two arms 14 of each pair. A cylindrical sleeve 15 may be mounted rotatably on each rod 16 for facilitating the locking and unlocking operations of the locking plate 13 to be described.

The arrangement is such that, when the hook portion 13' of the locking plate 13 is forced brought to engagement with the sleeve 15 on the locking rod 16 as shown in the drawings, the supporter ring 2 and the back cover 7 are forced toward each other, the holder ring 1 allowing necessary movement of the supporter ring 2 by virtue of its sliding fit with the latter, to compress the packing rings 6 and 9 with sufficient forces to establish water-tight seals thereby. For this purpose, the packing rings 6 and 9 should be made of resilient and water-impermeable material, such as rubber.

It will readily be seen that, according to the present invention, a positive water-tightness of a watch case is obtained with relatively a simple construction, with no fear of incidental failure in the water-tightness, as would be caused by loosening of set screws. In addition, sufiicient compressive forces are secured for the packing rings to establish positive water-tight seals. It has been found in practice that the watch case embodying the present invention is so water-tight that any water cannot enter into the case even when immersed in water as deep as meters, the water pressure thereat corresponding to about five atmospheric pressures. In addition, it will readily be understood that the locking and unlocking of the back cover 7, and consequently the assembling and disassembling of the watch casing 3 may be effected in a simple, easy and prompt manner.

I claim:

A water-tight wrist-watch case comprising a watch holder ring of substantially rectangular configuration, a supporter ring snugly fitting around said holder ring and provided with an upper internal flange and two opposite pairs of externally extending arms for watch-band connection, a glass plate with its peripheral portion held under said internal flange, a resilient packing ring interposed between said holder ring and the peripheral portion of said glass plate, a back cover having an upwardly extending flange around its periphery, a corresponding groove formed in said holder ring for receiving said upwardly extending flange, another resilient packing ring held between the bottom of said groove and said upwardly extending flange, a rod transversely mounted between each pair of said arms, a locking plate pivotally mounted on each of said rods and having a hooked free end, and locking rods fixedly mounted on said back cover for locking engagement with said hooked end of each of said locking plates, two opposite pairs of arms fixed to said back cover at its opposite sides and respective cylindrical sleeves rotatably mounted on said locking rods, said locking rods are respectively mounted between said pairs of arms fixed to said back cover, said cylindrical sleeves being engaged by the hooked ends of said locking plates, the arrangement being such that both of said packing rings are held under sufficient compression to secure water-tightness of the watch case.

References Cited in the file of this patent FOREIGN PATENTS Switzerland Jan. 16, 1942 Switzerland Apr. 16, 1942 Switzerland Jan. 3, 1948 Switzeralnd Jan. 3, 1948 Switzerland Sept. 16, 1948 Switzerland Aug. 1, 1949 

